I've just picked up a 91 Suburban R2500 with a 6.2 diesel
and a 4L80E 4 speed overdrive transmission.
I understand that the 4L80E has a tow/haul mode, but I can't
find any switch to engage this in my truck.
I called GM, and they say there was no tow/haul mode in 91.
Not that I don't trust GM ;-) but is this really true?
I'm wondering if my transmission does have this, but it just isn't
hooked up, and whether I can wire it up myself?
TIA for any and all replies/pointer/suggestions,